INFO: task hung in em28xx_i2c_unregister

Status: upstream: reported syz repro on 2026/08/31 21:17
Subsystems: i2c usb
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+f669f02a0fcc5b2148f2@syzkaller.appspotmail.com
First crash: 418d, last: 12h08m
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
bdcbff13 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ INFO: task hung in em28xx_i2c_unregister 2026/05/25 00:22 2026/05/25 00:22 2026/05/25 00:38 c69befb3
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [i2c?] [usb?] INFO: task hung in em28xx_i2c_unregister 0 (1) 2026/08/31 21:17
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 INFO: task hung in em28xx_i2c_unregister 1 1 228d 228d 0/2 auto-obsoleted due to no activity on 2026/04/25 08:32

Sample crash report:
INFO: task kworker/1:3:1865 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:3     state:D stack:22152 pid:1865  tgid:1865  ppid:2      task_flags:0x4288060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7362
 schedule_timeout+0xc0/0x2c0 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common kernel/sched/completion.c:121 [inline]
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion+0x2ca/0x5e0 kernel/sched/completion.c:153
 i2c_del_adapter+0x281/0x430 drivers/i2c/i2c-core-base.c:1841
 em28xx_i2c_unregister+0x4b/0x60 drivers/media/usb/em28xx/em28xx-i2c.c:1029
 em28xx_release_resources+0x14c/0x240 drivers/media/usb/em28xx/em28xx-cards.c:3764
 em28xx_usb_disconnect+0x19f/0x2f0 drivers/media/usb/em28xx/em28xx-cards.c:4455
 usb_unbind_interface+0x295/0x9f0 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:618 [inline]
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x4f5/0x880 drivers/base/dd.c:1372
 bus_remove_device+0x444/0x560 drivers/base/bus.c:664
 device_del+0x524/0x8f0 drivers/base/core.c:3965
 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1478
 usb_disconnect+0x346/0x9a0 drivers/usb/core/hub.c:2350
 hub_port_connect drivers/usb/core/hub.c:5420 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
 port_event drivers/usb/core/hub.c:5884 [inline]
 hub_event+0x1bbb/0x4d30 drivers/usb/core/hub.c:5966
 process_one_work kernel/workqueue.c:3387 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task syz.4.136:6293 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.136       state:D stack:27896 pid:6293  tgid:6293  ppid:5809   task_flags:0x400040 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7362
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7419
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 device_lock include/linux/device.h:1104 [inline]
 usbdev_release+0x80/0x780 drivers/usb/core/devio.c:1099
 __fput+0x418/0xa50 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 ptrace_notify+0x27c/0x2b0 kernel/signal.c:2524
 ptrace_report_syscall include/linux/ptrace.h:416 [inline]
 ptrace_report_syscall_exit+0x2d/0x50 include/linux/ptrace.h:477
 arch_ptrace_report_syscall_exit include/linux/entry-common.h:233 [inline]
 syscall_exit_work include/linux/entry-common.h:266 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:297 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:334 [inline]
 do_syscall_64+0x4a0/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd16879e159
RSP: 002b:00007fd168b4fba8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fd168b4fc90 RCX: 00007fd16879e159
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000004d940 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b2e620000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd168a25fac R14: 00007fd168a25fa8 R15: 00007fd168a25fa0
 </TASK>
INFO: task syz.2.135:6294 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.135       state:D stack:27096 pid:6294  tgid:6294  ppid:5785   task_flags:0x400040 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7362
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7419
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 device_lock include/linux/device.h:1104 [inline]
 usbdev_release+0x80/0x780 drivers/usb/core/devio.c:1099
 __fput+0x418/0xa50 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 ptrace_notify+0x27c/0x2b0 kernel/signal.c:2524
 ptrace_report_syscall include/linux/ptrace.h:416 [inline]
 ptrace_report_syscall_exit+0x2d/0x50 include/linux/ptrace.h:477
 arch_ptrace_report_syscall_exit include/linux/entry-common.h:233 [inline]
 syscall_exit_work include/linux/entry-common.h:266 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:297 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:334 [inline]
 do_syscall_64+0x4a0/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1b3299e159
RSP: 002b:00007f1b32d4fba8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f1b32d4fc90 RCX: 00007f1b3299e159
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000004d997 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b2d220000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1b32c25fac R14: 00007f1b32c25fa8 R15: 00007f1b32c25fa0
 </TASK>
INFO: task syz.5.133:6295 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.133       state:D stack:27096 pid:6295  tgid:6295  ppid:5796   task_flags:0x400040 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7362
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7419
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 device_lock include/linux/device.h:1104 [inline]
 usbdev_release+0x80/0x780 drivers/usb/core/devio.c:1099
 __fput+0x418/0xa50 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 ptrace_notify+0x27c/0x2b0 kernel/signal.c:2524
 ptrace_report_syscall include/linux/ptrace.h:416 [inline]
 ptrace_report_syscall_exit+0x2d/0x50 include/linux/ptrace.h:477
 arch_ptrace_report_syscall_exit include/linux/entry-common.h:233 [inline]
 syscall_exit_work include/linux/entry-common.h:266 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:297 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:334 [inline]
 do_syscall_64+0x4a0/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe6b1f9e159
RSP: 002b:00007fe6b234fba8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fe6b234fc90 RCX: 00007fe6b1f9e159
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000004d99d R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b2dd20000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe6b2225fac R14: 00007fe6b2225fa8 R15: 00007fe6b2225fa0
 </TASK>
INFO: task syz.0.132:6296 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.132       state:D stack:27096 pid:6296  tgid:6296  ppid:5770   task_flags:0x400040 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7362
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7419
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 device_lock include/linux/device.h:1104 [inline]
 usbdev_release+0x80/0x780 drivers/usb/core/devio.c:1099
 __fput+0x418/0xa50 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 ptrace_notify+0x27c/0x2b0 kernel/signal.c:2524
 ptrace_report_syscall include/linux/ptrace.h:416 [inline]
 ptrace_report_syscall_exit+0x2d/0x50 include/linux/ptrace.h:477
 arch_ptrace_report_syscall_exit include/linux/entry-common.h:233 [inline]
 syscall_exit_work include/linux/entry-common.h:266 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:297 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:334 [inline]
 do_syscall_64+0x4a0/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa0c859e159
RSP: 002b:00007fa0c894fba8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fa0c894fc90 RCX: 00007fa0c859e159
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000004d9a7 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b2c820000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa0c8825fac R14: 00007fa0c8825fa8 R15: 00007fa0c8825fa0
 </TASK>
INFO: task syz.1.134:6297 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.134       state:D stack:27592 pid:6297  tgid:6297  ppid:5775   task_flags:0x400040 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7362
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7419
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 device_lock include/linux/device.h:1104 [inline]
 usbdev_release+0x80/0x780 drivers/usb/core/devio.c:1099
 __fput+0x418/0xa50 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 ptrace_notify+0x27c/0x2b0 kernel/signal.c:2524
 ptrace_report_syscall include/linux/ptrace.h:416 [inline]
 ptrace_report_syscall_exit+0x2d/0x50 include/linux/ptrace.h:477
 arch_ptrace_report_syscall_exit include/linux/entry-common.h:233 [inline]
 syscall_exit_work include/linux/entry-common.h:266 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:297 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:334 [inline]
 do_syscall_64+0x4a0/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa70379e159
RSP: 002b:00007fa703b4fba8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fa703b4fc90 RCX: 00007fa70379e159
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000004d9ba R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b2cb20000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa703a25fac R14: 00007fa703a25fa8 R15: 00007fa703a25fa0
 </TASK>

Showing all locks held in the system:
locks held by pr/ttyS0/16: 2, last CPU#1:
 #0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
 #0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
 #0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291
 #1: ffffffff9ad31098 (&port_lock_key){-...}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
 #1: ffffffff9ad31098 (&port_lock_key){-...}-{3:3}, at: univ8250_console_device_lock+0x67/0xc0 drivers/tty/serial/8250/8250_core.c:413
locks held by khungtaskd/32: 1, last CPU#0:
 #0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6837
locks held by kworker/1:3/1865: 6, on CPU#1:
 #0: ffff8880232e7140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff8880232e7140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff8880232e7140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #0: ffff8880232e7140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
 #1: ffffc900063f7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc900063f7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc900063f7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #1: ffffc900063f7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
 #2: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #2: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5912
 #3: ffff888024c051d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #3: ffff888024c051d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xfc/0x9a0 drivers/usb/core/hub.c:2341
 #4: ffff88802b4031a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #4: ffff88802b4031a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline]
 #4: ffff88802b4031a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369
 #5: ffff888058201cf0 (&dev->lock#3){+.+.}-{4:4}, at: em28xx_release_resources+0x75/0x240 drivers/media/usb/em28xx/em28xx-cards.c:3758
locks held by getty/5374: 2, on CPU#0:
 #0: ffff888036cae0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by udevd/6066: 4, on CPU#1:
 #0: ffff888035016f38 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xa4/0xca0 fs/seq_file.c:183
 #1: ffff888055824c80 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5d/0x420 fs/kernfs/file.c:165
 #2: ffff88807ff67a58 (kn->active#28){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
 #2: ffff88807ff67a58 (kn->active#28){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:166
 #3: ffff888024c051d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1109 [inline]
 #3: ffff888024c051d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
locks held by syz.4.136/6293: 1, on CPU#0:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_release+0x80/0x780 drivers/usb/core/devio.c:1099
locks held by syz.2.135/6294: 1, on CPU#0:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_release+0x80/0x780 drivers/usb/core/devio.c:1099
locks held by syz.5.133/6295: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_release+0x80/0x780 drivers/usb/core/devio.c:1099
locks held by syz.0.132/6296: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_release+0x80/0x780 drivers/usb/core/devio.c:1099
locks held by syz.1.134/6297: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_release+0x80/0x780 drivers/usb/core/devio.c:1099
locks held by syz.6.137/6384: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.7.138/6385: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.8.139/6386: 1, on CPU#0:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.9.140/6387: 1, on CPU#0:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.3.141/6388: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.0.142/6484: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.1.143/6485: 1, on CPU#0:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.2.144/6486: 1, on CPU#0:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.4.146/6490: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.6.150/6564: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.7.151/6565: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.8.153/6566: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.9.154/6567: 1, on CPU#0:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.3.162/6643: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.0.163/6645: 1, on CPU#0:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.1.164/6646: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.2.166/6648: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.4.174/6724: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.7.176/6725: 1, on CPU#0:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.6.175/6726: 1, on CPU#1:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054
locks held by syz.8.178/6727: 1, on CPU#0:
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #0: ffff88802a64a1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x770 drivers/usb/core/devio.c:1054

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 16 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409
Code: e8 5e e2 55 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 af ab c5 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 1a e4 74 06 cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900001578b8 EFLAGS: 00000002
RAX: 1ffffffff35a6200 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff8571d400 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9ad310c0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888124dda000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe39d825fa4 CR3: 000000006a5fc000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 serial_in drivers/tty/serial/8250/8250.h:128 [inline]
 serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
 wait_for_lsr+0x184/0x2f0 drivers/tty/serial/8250/8250_port.c:2013
 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3270 [inline]
 __serial8250_console_fifo_write+0x346/0x3e0 drivers/tty/serial/8250/8250_port.c:3372
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
 __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline]
 serial8250_console_write+0xaa1/0x1200 drivers/tty/serial/8250/8250_port.c:3493
 nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
 nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
 nbcon_kthread_func+0x679/0x880 kernel/printk/nbcon.c:1271
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (29):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/31 09:31 upstream a23cbb05744b 2f52988a .config strace log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_i2c_unregister
2026/08/31 06:26 upstream a23cbb05744b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_i2c_unregister
2026/08/12 12:02 upstream f5bbbfec59b4 f8d35649 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in em28xx_i2c_unregister
2026/06/16 15:25 upstream 481329ec5b31 50bb0618 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_i2c_unregister
2026/04/04 02:19 upstream 631919fb12fe 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in em28xx_i2c_unregister
2026/03/29 18:00 upstream cbfffcca2bf0 356bdfc9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in em28xx_i2c_unregister
2026/03/12 17:19 upstream 80234b5ab240 4efadf07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in em28xx_i2c_unregister
2026/02/16 22:23 upstream 0f2acd3148e0 5d52cba5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in em28xx_i2c_unregister
2026/02/02 00:00 upstream 9f2693489ef8 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_i2c_unregister
2026/01/07 15:57 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_i2c_unregister
2025/12/05 11:10 upstream aa833fc394ba d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_i2c_unregister
2025/11/26 01:58 upstream 8a2bcda5e139 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_i2c_unregister
2025/11/02 14:40 upstream 691d401c7e0e 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_i2c_unregister
2025/10/07 22:33 upstream 971199ad2a0f 8ef35d49 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_i2c_unregister
2025/09/26 12:14 upstream 4ff71af020ae 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_i2c_unregister
2025/08/26 12:26 upstream fab1beda7597 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_i2c_unregister
2025/08/15 00:41 upstream 0cc53520e68b dcc075fb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_i2c_unregister
2025/07/09 10:23 upstream 733923397fd9 abade794 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_i2c_unregister
2026/07/06 02:46 upstream f105f3631d51 fcece630 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in em28xx_i2c_unregister
2026/06/09 03:42 upstream 4549871118cf 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in em28xx_i2c_unregister
2026/06/09 03:35 upstream 4549871118cf 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in em28xx_i2c_unregister
2026/06/09 03:27 upstream 4549871118cf 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in em28xx_i2c_unregister
2026/06/09 03:22 upstream 4549871118cf 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in em28xx_i2c_unregister
2025/12/17 12:06 upstream ea1013c15392 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in em28xx_i2c_unregister
2025/12/13 13:24 upstream 9551a26f17d9 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in em28xx_i2c_unregister
2025/08/19 16:13 upstream be48bcf004f9 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in em28xx_i2c_unregister
2026/07/10 00:08 linux-next 34cf6dafc474 4167ee25 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in em28xx_i2c_unregister
2025/07/15 14:21 linux-next 0be23810e32e 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in em28xx_i2c_unregister
2025/07/15 12:48 linux-next 0be23810e32e 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in em28xx_i2c_unregister
* Struck through repros no longer work on HEAD.